The biochemistry of build-up and breakdown of chitinous insect cuticle during molting will be studied. Investigation of the neutral protease first demonstrated in this laboratory will be advanced; molting fluid chitinase, already partially purified will also be further studied. Discovery of the protease has led to promising feeding trials. Chitin synthesis will also be further elucidated. This two-pronged approach is aimed at delineation of the biochemistry of arthropod molting in order to permit the rational design of insecticides and antimycotics. One of the chief features that distinquish arthropods from vertebrates is the possession of a chitinous exoskeleton which must periodically be molted, i.e. replaced; fungi, too, are protected by a tough chitinous covering. Arthropods and fungi interact with man in a myriad of ways: as pollinators of food crops; as vectors or causative organisms of serious diseases such as malaria, typhus, plague, and mycoses; as parasites; as decomposers; as predators on harmful organisms; as essential links in food chains. Man in his efforts to control the harmful effects of these organisms, adversely affects his own health and well-being and that of other animals by use of broad-spectrum, highly poisonous chemicals, such as organochlorines and alkylmercurals. The studies in this laboratory are aimed at better understanding of a little known but vitally important facet of biochemistry so that quicker, surer, and more specific means may be found that will permit interference with harmful but not beneficial organisms. The very alienness of the biochemistry of chitin should thus be seen as an asset; its basic understanding will permit a rational instead of a sledgehammer approach to areas vitally affecting human health.